Quote Originally Posted by mrdevious
Actually, while I'm too stoned to remember right now, they found this fossil of this creature that was half bird and half reptile. but regardless, there is no evolution in the sense of "species A - turns to - species B", it's extremely small characteristics, often at the microscopic level, that are altered every so many years over millions of years. eventually after millions of years of this change, one species is not going to look like it did in the beginning. This is because of an indisputable fact: mutations (alterations in the genetic code) happen, and creatures with a geneticly advantageous attribute will survive and find mates to become dominant in the gene pool.
Exactly. I've heard the creationist Kent Hovind try to debate this point, and he'll start out by saying something like "We only observe animals giving birth to the same kind", that is, we don't see organisms giving birth to new organisms of a different species. We only see minor changes happening from one generation to the next, and for some reason he thinks these minor changes can't build up among separated groups to the point where they can no longer interbreed.

I like to draw an analogy here with linguistic evolution for two reasons. First, I'm a linguistics major and I know a lot about how languages change over time. Second, linguistic change happens a lot faster than biological change, and we have observed the linguistic equivalent of speciation. We have historical documents showing how, over time, Latin slowly changed into the languages we now call French, Spanish, Portuguese, Italian, and Romanian, which are not mutually intelligible at all, even though at every point along the line parents were always capable of communicating with their children.

Of course it was never the case that two Latin-speaking parents gave birth to a French-speaking child, because the difference is not that clear-cut. Every generation spoke a slightly different form of the language than their parents did (this process is still going on; witness the replacement of "groovy" and "far out" with "chill" and "whack"). While the Roman Empire still existed, people would travel all over the Empire and this kept the language relatively uniform, in the same way that a species will not have much trouble interbreeding over a large area if the organisms can freely move around in it. We no longer fear England and America developing their own different languages because they communicate with each other all the time. This was not always the case, which is why we have slightly different versions of English, and if something stopped that communication it is likely that they would develop into two separate languages.

After the Roman Empire fell, very few people ever traveled more than a few miles away from their hometowns. People in Spain stopped communicating with people in France, who stopped communicating with people in Italy, and so forth. With this lack of communication, there was nothing to prevent each area from changing the language in their own unique ways. Over the centuries they gradually developed radically different dialects of Latin, often separated by geographical barriers like mountains and rivers. As the changes in each dialect built up over time, they became separate languages, giving rise to the variety of Romance languages we see today.

Species evolve in much the same way. If a group gets separated from the rest of the species by some geographical barrier and ceases to interbreed with it, that group will gradually change over time to adapt to its new environment. Eventually these tiny changes will build up to the point that the two groups will no longer be able to interbreed if they do come into contact with each other again. I can't think of anything that could prevent such a chain of events from happening, short of the intervening hand of Jehov—err, the "Intelligent Designer".

The creationists love to bring up the argument that there are "gaps" between organism A and organism B in the fossil record. And even when we do find organism C which fills the gap, they will claim that there are now two gaps: one between organisms A and C, and one between organisms C and B. And if we fill those two gaps with fossils, there are now four gaps for the creationists to complain about. They want us to come up with all forms of a species' evolutionary heritage somewhere in the fossil record. In reality, it is so rare that any organism gets fossilized and the fossil survives that such an expectation is absolutely ridiculous. Species change gradually. There is no cut-off point where we can say, "this organism was of species A and its child was of species B". That would be like looking at historical documents and trying to find the exact moment that Latin turned into French or looking at the color spectrum and trying to find the exact point where green turns into blue. You just can't do it, because it's a gradual change.
Oneironaut Reviewed by Oneironaut on . Would an Athiest be an Evolutionists? "THOUGHTS ON EVOLUTION" Adapted from the book; Lifeā??s Story by Mark Haville A coral reef is one of the worlds many interdependent eco-systems. An eco-system is an environment which contains a variety of life-forms that cannot survive without each other. Ultimately the whole earth is an eco-system delicately balanced to sustain life. A relationship where creatures depend on each other for survival is called symbiosis. Of course if different creatures depend on each other to stay alive now, Rating: 5